The commercial application of enzymes as a feed additive has a history of less than 20 years. During this period, the feed enzyme industry came into existence and it has gone through several phases of development. The first phase was the use of enzymes to enhance nutrient digestibility, focusing primarily on removing the anti-nutritive effects of non-starch polysaccharides (NSP), such as arabinoxylans and β-glucans, from broiler diets based on viscous grains like wheat, rye, barley or triticale. During the early 1990s, the scope of enzyme application expanded to consider nutrients other than NSP and benefits other than digestibility enhancement. Phytase is a prime example, where not only was it used to increase the utilisation of phtate P, but also to alleviate environmental burdens by reducing P excretion in the excreta. The industry then started to advocate enzyme addition to poultry diets based on non-viscous grains, such as sorghum and corn. Although such a use is not uncommon in some parts of the world, the industry is still in search for highly efficacious enzymes for non-viscous cereal grains. The next phase is the application of enzymes to non-cereal grain components of the diet. These vegetable protein sources are often high in NSP, which are poorly characterised in regard to their molecular structures. Significant progress has been made on characterisation of the NSP in soyabean, but the industry has not been able to produce commercially viable products that consistently improve the digestibility of vegetable protiens. The enzyme industry today is constantly searching for new areas of application. Some recent data demonstrate the role of glycanases (charbohydrate degrading enzymes) as an alternative to in-feed antibiotics. It is possible to produce enzymes tailored for (a) the generation of specific low molecular weight carbohydrates in vivo, which, in turn, produce specific health outcomes in birds; (b) de-activation of anti-nutrients other than NSP and phtate, and (c) degrading of non-conventional feed resources to yield ME. The development of enzyme technology needs to go hand in hand with better characterisation of substrate structures, the gut microflora, and the immune system.

The beginning of the 21st century is an appropriate time to review a century of poultry genetics, because it is one hundred years since Mendel's pioneering work was rediscovered and became part of the mainstream of science. Although, in my opinion, Mendel enjoyed more than a fair share of luck in reaching his conclusions, he nevertheless laid a foundation on which students of poultry, and many other species, were able to build a vast body of literature. Mendel's choice of the height of pea plants, in retrospect, was not a wise one. Here is a trait that is basically quantitative, and yet he was able to describe it, and reach his conclusions, in qualitative terms!

Education is one of the founding pillars of the World's Poultry Science Association (WPSA). The Association regards most of its activities as contributing to education. The Journal, now in its 62nd volume, presents review articles on a diverse array of subjects concerned with poultry science. In addition, the Journal contains details of upcoming educational courses at a variety of institutions around the globe.

World Congresses, Regional Conferences, Symposia and Workshops provide educational opportunities at a variety of academic levels. WPSA provides scholarship opportunities for young scientists to attend these events and also contributes to faculty support through its Speakers' Bureau Programme.

The Association also cooperates with the Dutch organization, Agromisa. Together they are producing poultry management manuals for use in developing countries. The International Network for Family Poultry Development operates in developing countries to improve poultry management at the village level, thereby raising the nutritional status, as well as economic activity, among some of the world's most vulnerable and poor people.

From this, it can be seen that the WPSAoperates at every level of poultry keeping, to improve the competence of those involved. These activities are supported by both the world and branch organizations.

Global poultry meat and egg production as well as trade with poultry products have shown a remarkable dynamic during the last 35 years. Between 1970 and 2005 poultry meat and egg production increased faster than that of beef and veal or pigmeat. The trade volume of poultry meat increased even faster than production. In 2004, 12% of the poultry meat produced reached the world market but only 1.8% of the eggs. The rapid increase in poultry meat production has been very imbalanced.

Whereas North and Central America as well as Europe lost market shares, China and Brazil became new centres of production in Asia and South America. In hen egg production Asia was the only winner in the analysed time period, all other continents lost market shares. The increase in regional concentration is mainly due to the dominating role of China. Developing countries surpassed developed countries in their production volume between 1990 and 2000. At the present time, they contribute about 55% to global poultry meat and 68% to egg production.

The trade volume of poultry products increased parallel to the rapid growth of global poultry meat and egg production. The regional concentration of poultry meat as well as egg exports and imports is very high. In contrast to production, the contribution of developing countries to the export volume of poultry products is still much lower than that of developed countries. Even though developing countries were able to gain higher market shares during the past 35 years, the regional shift from developed to developing countries has been less dramatic than that in poultry meat and hen egg production. Especially hen eggs are still mainly traded between European as well as Asian countries.

Outbreaks of Avian Influenza will have impacts on production and consumption, resulting in serious financial problems of major producers and new spatial patterns of production and trade flows. The full implementation of directive 1999/74/EU for laying hens will also have impacts on egg production and egg trade, as the EU will probably no longer be an egg surplus region but be forced to import.

Twenty four Chinese native duck breeds were studied to estimate genetic diversity and genetic structure using microsatellite markers. The genetic relationships between breeds were analyzed in combination with their geographic distribution. A total of 28 microsatellite markers were amplified. All the breeds exhibited genetic diversity, through the estimation of polymorphic information content (PIC) and mean heterozygosity (H) index. The mean genetic diversity of the populations was 0.569, while the PIC values for Chinese native duck breeds was relatively high. Neighbour-joining was used to calculate genetic distances. Cluster analysis divided the twenty-four populations into five groups, and the genetic relationships among the populations had obvious association with their phylogenetic relationship with historical relations and geographical distribution. The developmental history of native duck breeds in China appears to have had an effect on their genetic structure.

Malabsorption syndrome (MAS) is a multifactorial disease that causes intestinal disorders in broilers due to infection of the gastrointestinal tract with different infectious agents. The exact aetiology is unknown, although several viruses are isolated from MAS affected chickens. None of these isolated infectious agents alone inducted the malabsorption syndrome. MAS in broilers is characterised by poor growth and lesions in the GI-tract, mainly in the small intestine. Experimentally, MAS can be induced in one-day old broilers by oral inoculation of homogenates obtained from digestive tract tissues of MAS affected broilers. Susceptibility to the MAS syndrome differs between broiler lines. The susceptibility to MAS is correlated with the severity of the lesions, apoptosis and heterophil infiltration of the jejunum. Susceptibility to MAS is also related to the frequency of CD4 and CD8 positive T-cells in the intestinal villus and the mRNA expression level of different cytokines in control and in MAS induced broilers. With the use of micro-arrays differences in gene expression levels between broiler lines that differ in MAS susceptibility were observed. From these experiments genes that are immune and food absorption related were identified. If some of these genes or the T-cell population in the gut and the other MAS susceptible related parameters could predict or prevent MAS susceptibility in broilers needs to be further investigated but can be interestingly for breeding programmes.

Necrotic enteritis is a disease in poultry that can have a high economic and animal welfare cost, and has become increasingly prevalent in the European Union due to factors such as the removal of antibiotic growth promoters and the requirement to exclude animal by-products from diet formulations. Estimates of the prevalence of necrotic enteritis vary widely (1–40%) as does the cost of the disease, and the subclinical form may be the most important manifestation of the disease as this is likely to go undetected and hence untreated. An outbreak of necrotic enteritis is primarily associated with rapid proliferation of the anaerobic bacterium, Clostridium perfringens type A or C, leading to gaseous extension of the small intestine, the production of one or more exotoxins, and enteric toxicosis. The molecular progression of the disease is quite complex and at the bacterial level involves quorum sensing, toxin production and secretion, and interactions of the pathogen with the innate immune system of the chicken. Intestinal cell permeation by the toxin activates a series of intracellular pathways including protein kinase cascades, and ultimately results in cell death. The precise molecular signals that set off this cascade are still unclear. The various predisposing environmental, health and dietary factors that modify the gut environment and promote colonisation with C. perfringens, are discussed. With such a multi-factorial disease, a working and reproducible experimental model with which to study bacterial/host and dietary/host interactions is an essential tool in the search for appropriate control or management strategies for the poultry industry.

The hen's egg plays a crucial role in the embryonic development of the bird. It serves first as a source of energy and nutrients of high digestibility and, second, protects the embryonic bird against external aggressions. The unique structure of an egg with yolk containing the embryo surrounded by albumen and shell as physical barriers, is the first element of this protection. The second one consists of the specific composition of yolk, albumen and shell with many molecules possessing elevated biological properties. Thus, these molecules represent a major source of active principles usable by medical, pharmaceutical, cosmetic, nutraceutical and biotechnological industries. In this review, we will focus particularly on nutritional, health, and biotechnological activities of egg molecules and on the approaches, which are proposed by European research groups, to exploit this bioactive potential.

Abstract Red mite (Dermanyssus gallinae; De Geer, 1778) is currently one of the most detrimental ectoparasites in laying birds across several countries. Symptoms of D. gallinae infestation include reduction in production, poor egg quality, increased mortality and also a compromise to welfare. Feeding on its host for only short periods of time, the red mite spends the vast proportion of its short life-cycle hidden deep within the house substructure. For this reason, it is the preference of red mite to occupy free range or barn systems as opposed to caged, since a greater number of potential hiding places can be sought. A problem which will therefore be amplified within the EU with the impending ban on production in laying cages. This, in conjunction with concern over resistance to acaricides, toxicity risks and acaricide withdrawal, make control particularly problematic and financially draining for producers. Therefore alternative methods must be sought, such as vaccine development. However, in order for this to be achieved, an understanding of mite antigenicity must first be established.

Thus, the purpose of this study was to assess immunological response of humeral antibodies to naturally occurring mite antigens, using enzyme-linked immunosorbent assay (ELISA) and SDS-PAGE. Antibodies were derived from egg yolk and blood sera which were collected from commercial laying farms across the UK with varying levels of red mite infestation and using different production systems (caged, barn and free range). In addition, mites were trapped and counted periodically so as to follow population dynamics over a flock lifespan in conjunction with a series of production measures (Laying percentage, eggs per bird per week, mortality and temperature). The results describe the effect of red mite infestation on production parameters, immunological response and the relationship between them.

The impact of practically all the everyday stress factors occurring in the first days of the chick life on the rate of the utilisation of the yolk sac content, on the chicken immune status and on the growth of the animal's body and intestinal masses was investigated. The impact of the stress was investigated during the first five days of chick's life. The chicks were divided into five groups, each comprising 44 birds. The first chick group was exposed to moderate cold (2–3°C below the optimal temperature for the chick age). The second group was exposed to moderate heat (2–3°C above the optimal temperature for the age). The third and fourth group were deprived of feed and drinking water for 12 hours and 24 hour, respectively. The fifth chick group was the control group: the birds in this group had optimal environmental conditions and received feed and drinking water immediately upon entering the trial. Ten chicks were taken every day and weighed. Their blood samples were obtained for the assessment of infectious bursal disease virus antibody titres using ELISA method. After that, the birds were sacrificed, their intestinal masses weighed and the quantity of resorbed yolk measured.

The greatest body and intestinal masses were found in the control animals. The body and intestinal masses were the lowest in the group which was denied water and food for 24 hours. The resorption of the yolk sac content was approximately equal in all the chick groups, but the resorption rate varied by days. The highest resorption was observed in the chick groups on the day when feed was denied to them, so that this high resorption could be associated with the bird's body energy requirements. The resorption of the remaining yolk is associated with feed intake: in chicks to which feed is withheld the yolk is resorbed through the yolk sac wall directly into the blood, which increased its usability. When energy requirements are not satisfied, the chick's body probably utilises resorbed antibodies from the yolk remnants, as their glycoprotein composition is suitable for this purpose.

In four studies, we evaluated the influence of dietary MOS on the performance of turkeys and their intestinal health status at various stages of the production. Turkey growth, feed efficiency and large intestine parameters were examined after 4-, 8- and 16-week administration of diets with different levels (0.1 to 1.0%) of a MOS. The experimental 4- and 8-week feeding with various levels of MOS (up to 0.5%) did not affect the productivity of the birds, yet medium (0.4 and 0.2% in the first and second 8-wk periods, respectively) and high (1.0 and 0.4% in the first and second 8-wk periods, respectively) levels of dietary MOS were found to significantly increase live body weight after feeding for 16 weeks. At the age of 8 weeks, we observed a similar effect of MOS and inulin on the productivity parameters. The caecal metabolism was affected by dietary mannan variously depending on the dose of MOS and the age of birds. Generally, the dietary mannan-oligosaccharides more considerably changed caecal metabolism at early ages. At 4 weeks of age, we found some positive effects of adding MOS to the diet, such as lowering ammonia concentration and decreasing β-glucuronidase activity in the caeca, as well as some negative effects, including decreased bacterial glycolytic activity and raised pH of digesta. In our 8-week experiment, non-linear changes were observed in the parameters of caecal digesta at different doses of MOS. It seems that dietary supplementation with 0.25% MOS, compared to other doses, exerted a specific effect on gut-colonizing microflora enhancing its proliferation and activity, which has been reflected in a higher concentration of Lowry's protein and an increased glycolytic activity. After feeding the turkeys for 16 weeks, their caecal metabolism was affected by dietary MOS to some extent. Although MOS did not change the caecal pH or the bacterial enzyme activity, when applied at medium and higher doses it decreased ammonia as well as SCFA concentration (mainly acetate) in the caecal digesta. Dietary MOS had no significant effect on the caecal populations of Bifidobacterium and Lactobacillus, whereas the populations of caecal E. coli were observed to decrease, especially upon medium and high experimental concentrations.

Proteins in solution can form objects of various shapes. One fascinating possibility is the formation of fibres with a length up to micrometers, but with a thickness of a few nanometres, therefore referring to them as nano-fibres. Many proteins show this behaviour under the appropriate conditions. Gel properties of nano-fibre containing systems can be manipulated by adjusting the fibre properties. The systems exhibit particular behaviour under flow, which can be utilised in processing. Such nanofibres have innovation potential for foods in terms of for example extremely low weight fraction gels, and their presence may give rise to unexpected novel, including sensory related, material properties.

Beak trimming is routinely practiced in the poultry industry to reduce the incidence of feather pecking, aggression, and cannibalism in egg layers. Feather pecking is painful to birds and potentially induces cannibalism. Cannibalism happens in all current housing environments, cage- and free-production systems, and is one of the major causes of bird death in commercial laying hens without beak trimming. However, beak trimming has solicited a great deal of debate concerning the relative advantage and disadvantage of the practice and its impact on welfare. Abird's beak is a complex functional organ with an extensive nerve supply and various sensory receptors. Beak trimming may cause pain (acute, chronic, orboth) in trimmed birds due to tissue damage and nerve injury. The complexity and plasticity of the nervous system and the animal's inability to communicate verbally make pain difficult to measure directly. However, pain in animals can be recognized and assessed using physiological and behavioural parameters in response to noxious events. When evaluating whether an animal is experiencing pain, a distinction should be made between what an animal may feel and what a human observing the animal may feel. It should be noted that beak trimming-induced pain in birds is genetic-, lesion-, and age-dependent. Based on the updated information, the authorwould like to indicate that 1 with some genetic flocks of laying hens, if beak trimming is needed to prevent featherpecking and cannibalism, it should be conducted at hatchery oryoungerthan 10 days of age; 2 however, the most desirable approach is to eliminate beak trimming through a genetic selection of birds with less cannibalistic and aggressive tendencies, and 3 another solution is to develop an alternative means of trimming that has fewer painful implications and safeguards welfare before non-cannibalistic stocks are commercially available.

A first product of this European project was a tool for scoring chick quality. A link was established between chick quality and embryonic physiological parameters such as heat production. Eggs from broiler breeders that give rise to rapidly growing broilers have a different embryonic development that may need modified incubation conditions. Within genotypes, better chick quality induces better liveability and faster growth in broiler production. Extensive data on broiler breeder production were generated. Feed restriction was necessary to maintain welfare and reproduction at acceptable levels in standard broiler breeders. The dw-experimental genotype (E) was more tolerant to ad libitum feeding. If an alternative to feed restriction had to be found, the use of a dw genotype with less severe feed restriction could be adopted. Fibre per se, or partial feed restriction during the growing period, only compensated to a small extent for the negative effects of early fast growth on later reproduction. The results of the project on behaviour did not support welfare concerns on feed restriction. They confirmed the hypothesis that environmental pecking is a displacement activity rather than a sign of frustration. Factors other than central control by pituitary hormones seem to be involved in the modulation of the laying rate. The local (intra-ovarian) role of growth factors such as Insulin-like Growth Factors (IGFs), Bone Morphogenetic Proteins (BMPs) and leptin are known to modulate the effect of gonadotrophins on ovarian function. For both BMPs and IGFs, feed restriction enhanced the interaction between growth factors and gonadotrophins as well as the proliferation of granulosa cells in vitro. Future genetic selection of broiler breeder production might aim at uncoupling the control of growth factors in the ovary from the selection for rapid growth to maintain or increase the growth rate of chicks without further penalising the already poor reproductive performance of broiler breeders. Putative quantitative trait loci for ovulation rate were identified in the project and may eventually facilitate selection by breeding companies for birds that could be fed enough feed to optimise their welfare.

The microbiological implications of using a small-scale bucket-style washer are reported forchicken eggs. On average, the bucket washerreduced the total bacterial numbers on the surface of eggs under manufacturer-recommended conditions from 5.36 log CFU egg-1 to 2.82 log CFU egg-1. No evidence of enhanced bacterial contamination of the egg contents was found when microbiological examination was undertaken a few hours afterwashing. When washing visibly soiled free-range eggs, there was a tendency forthe wash-waterto become dirty afteronly a few batches of eggs had been washed. Washing in dirty water could increase the numbers of bacteria on the surfaces of those shells which were visibly clean before washing. These additional shell-surface bacteria however, were not detected in the egg contents (n=1032), when analyses were undertaken 1–2 hours after washing. In contrast, when washed eggs were stored for2 weeks at 15°C, we found that bacterial numbers in the egg contents were elevated when compared with unwashed controls. To determine if cool washing temperatures could cause water to taken up by egg contents, eggs were warmed to 37°C, 30°C, 25°C or 20°C and were submerged in aqueous protein stain at 15°C forup to 7 minutes. We did not observe take up of the stain solution unless its temperature was 15°C cooler than the egg contents and the eggs were immersed forat least 3 minutes.

The review addresses the fundamental process of ‘imprinting’. In his classical studies on newly hatched goslings Konrad Lorenz analysed the development of social binding and established the term ‘imprinting’ to describe this process. One of his major ideas was that imprinting occurs in ‘critical periods’, which are limited and severely restricted to the animal's very early life. For some time past, the term ‘imprinting’ is also used for an epigenetic mechanism, the ‘genomic imprinting’, which can be simply defined as gamete-of-origin dependent modification of genotype. Furthermore, in the course of the perinatal period ‘imprinting’ of physiological control systems occurs. Functional systems of the organism develop from open loop systems without feedback control into closed systems controlled by feedback mechanism. During ‘critical periods’, the actual environment influences the development of the respective physiological control systems for the entire life period, especially by changes in neuroorganization and expression of related effector genes. On the one hand, these mechanisms may cause perinatal malprogramming, which has been related to, e.g., metabolic disorders and cardiovascular diseases during later life in humans as well as in animals. On the other hand, knowledge on these mechanisms might be specifically used to induce long-term adaptation of the organism, for instance, to the postnatal climatic conditions (epigenetic temperature adaptation). Furthermore, the question if ‘critical period’ and ‘sensitive period’ are synonymous or different, and problems of identifying these developmental windows are discussed. Environmental manipulation of immature physiological mechanisms may be a physiological tool for characterization of ‘critical periods’.

Selection for fast early growth rate and feeding and management procedures which support growth have lead to various welfare problems in modern broiler strains. Problems which are directly linked to growth rate are metabolic disorders causing mortality by the Sudden Death Syndrome and ascites. Fast growth rate is generally accompanied by decreased locomotor activity and extended time spent sitting or lying. The lack of exercise is considered a main cause of leg weakness, and extreme durations of sitting on poor quality litter produces skin lesions at the breast and the legs. Management factors which slow down early growth alleviate many welfare problems. Alternatively it may be considered to use slow growing strains which do not have the above mentioned welfare problems. Since growth is a main economical factor, there are problems of acceptability of these measures in the commercial broiler production. Stocking density is a central issue of broiler welfare. It is evident, that the influence of stocking density on growth rate and leg problems acts through its influence on litter and air quality. High moisture content of the litter enhances microbial activity, which in turn leads to increase of temperature and ammonia in broiler houses, and thus, high incidence of contact dermatitis. High stocking density impedes heat transfer from the litter surface to the ventilated room. This restricts the efficacy of conventional ventilation systems in alleviating heat stress. Lighting programmes with reduced photoperiods are considered essential for the stimulation of locomotor activity and the development of a circadian rhythm in the birds. Extended dark periods, however, reduce growth when applied in the first weeks of age. Compensation occurs when the time of the production cycle is substantially increased. Various methods to enrich the environment have shown only moderate effects on the behaviour and physical conditions of broilers.

Feeding time has the potential to influence the performance of adult broilerbreeder flocks and is thus of great importance. Aliterature review is presented concerning the responses of adult broilerbreeders to feeding time. It appears that there is no benefit in feeding broiler breeders later in the day with regard to egg numbers oregg weight.

There is a potential improvement in shell quality that results from feeding laterin the day or from splitting the daily feed allocation across more frequent feeding periods throughout the day. However, anticipated improvements in shell quality due to delayed feeding times may not be realised, particularly when birds are housed on litter floors. Furthermore, improvements in shell quality may not be translated into improvements in hatchability due to increases in shell thickness adversely affecting the watervapourconductance of the eggshell.

Broiler hatching egg producers should be aware that later feeding times may delay the time of oviposition, which may demand changes in farm procedures. Furthermore, delayed feeding times may result in feeding activity coinciding with other important periods of activity, such as mating and oviposition, resulting in a reduction in fertility and an increase in the production of eggs with abnormal shells. The current commercial practice of feeding adult broiler breeders early in the day, at, ornear, lights-on, is justified, as feeding at this time has positive consequences for other aspects of hatching egg production. However, afternoon feeding is not necessarily detrimental and may be an option to consider in cases where improvements in shell quality are required, although this may not be the solution for hatchability problems. If a change in feeding time is under consideration, environmental conditions, particularly the photoperiod and ambient temperature, must be taken into account, and any changes should be made gradually, as broiler breeders may be sensitive to abrupt changes in feeding time. Furthermore, changes in the feeding schedule should be accompanied by close monitoring of performance parameters, including the number of settable, abnormal and floor eggs, percentage of fertile eggs, and hatch of fertiles.

Modern fast-growing meat-type broiler chickens are facing difficulties in coping with heat stress. The increase in broiler growth rate increases their body heat production. The global environmental temperature is also showing an upward trend. This situation demands an efficient means to economically improve the thermotolerance of broiler chickens in hot climates without affecting their productivity. Different managemental techniques and dietary modifications have been employed to overcome the adverse effects of heat stress. These strategies may often have proved beneficial but not all the time. Some of them even increased the cost of production. Many of these techniques did not show promising results, especially at higher ambient temperatures. This is probably due to not considering the loss of electrolytes during the periods of heat stress when panting birds are experiencing respiratory alkalosis. During heat stress, the loss of carbon dioxide (CO2) through respiration and bicarbonate ions coupled with monovalent cations (particularly sodium and potassium) through urine, disturbed the acid-base balance (respiratory alkalosis). The corrections in blood acid-base balance have been achieved by electrolyte supplementation, either through drinking water or feed. These electrolytes, in different amounts and proportions, proved beneficial for broilers under different heat stress regimens. The proportions of sodium, potassium and chloride in diets determine the dietary electrolyte balance (DEB=sodium plus potassium minus chloride, milliequivalents per kg). The discrepancies exist among different research workers about an appropriate DEB for heat-stressed broilers. Different environmental conditions in which broilers are reared; heat stress regimens (cyclic, acute, chronic), feeding regimens, source of electrolyte salts, combination of different electrolyte sources and the bird's genotype itself are factors that influence the requirements of a particular electrolyte as well as their balance in the diet. This review considers the usefulness and limitations of DEB equation, and the impact of different DEB on live performance, carcass characteristics, mortality and blood parameters in broilers reared under heat stress environments.

Oxidative rancidity represents one of the major causes of deterioration in food for human consumption. Besides producing unpleasant odours, it is responsible for losses in flavour, texture, consistency, appearance and nutritional value. In a similar way, in living animals, oxidative stress constitutes an important mechanism that leads to biological damage, and is regarded as one of the causes of several pathologies that affect poultry growth. Therefore a better understanding of lipid and protein oxidation processes will allow the use of antioxidants to handle and control them. This is fundamental in order to guarantee the quality and safety of meat for human consumption, and in turn the prevention and/or delay of several oxidation processes would allow its management for an optimal quality and shelf life conservation.